The present invention is directed to a lock cover mechanism for covering a lock, including a lock cylinder having a key opening, and more particularly to such a mechanism which includes a pivotally mounted cover plate and a cover plate detent arrangement for holding the cover plate in an opened position during actuation of the lock.
Lock cover mechanisms of the type to which the present invention is directed are commonly used to cover key openings of locks which latch vehicle body deck lids. Such a lock normally maintains the deck lid in closed position. A number of different cover mechanisms have been utilized in the past in which a detented cover assembly shields the lock from inclement weather conditions. Such a cover assembly generally includes a support plate mounted on the lock or the vehicle body deck lid. The support plate defines an access opening which is aligned with the lock key opening and through which a key is inserted into the lock. A cover plate is pivotally supported by the support plate and is moveable about an axis, generally normal to the plane of the cover plate, between an opened position in which a key may be inserted into the key opening, and a closed position in which the lock is completely covered.
One such detented cover assembly is disclosed in U.S. Pat. No. 3,898,824, issued Aug. 12, 1975, to Borlinghaus. In the '824 device, a leaf spring arrangement, mounted on the support plate, holds the cover plate open against the closing bias of a torsion spring after the cover has been manually opened. The leaf spring includes a detenting portion that is normally located in the path of the cover plate to prevent the plate from rotating into its closed position. The leaf spring further includes a portion adapted to be engaged and pushed outwardly from the deck lid by a cam on the lock cylinder as the cylinder is rotated into its unlocked position. The outward camming of this position of the leaf spring causes the detenting portion of the leaf spring to be moved inwardly toward the deck lid so that of the cover plate under the bias of the torsion spring.
The '824 cover assembly is disadvantageous in that the cover plate is released to move toward its closed position when the lock cylinder is rotated fully. At this point the key is still in the key opening, and the cover plate therefore moves into contact with the key. The key must then be rotated back to its vertical position and withdrawn from the key opening. Both of these steps are hindered by the key being contacted by the cover plate. Additionally, if the key is a two-sided key, over a period of time the rubbing of the edge of the key across the edge of the cover plate may damage the key. This detented cover assembly is further disadvantageous in that it requires a specially configured lock cylinder.
U.S. Pat. No. 3,930,391, issued Jan. 6, 1976, to Borlinghaus discloses a similar cover arrangement. In the '391 arrangement, however, an engagement portion of the leaf spring is positioned to contact the key as the lock cylinder is rotated during the unlocking operation. While not requiring a specially configured lock cylinder, the '391 arrangement is disadvantageous in that the body of the key is actually contacted by the leaf spring during rotation of the key, and this makes the rotation of the key somewhat more difficult. Additionally, the Borlinghaus '391 cover assembly, like the Borlinghaus '824 cover assembly, releases the cover plate when the key and lock cylinder are fully rotated, permitting the cover plate to move toward its closed position and strike the key. Thus, deterioration of the key and the cover plate over a period of time result as the key is repeatedly withdrawn from the key opening.
Accordingly, it is seen that there is a need for a cover mechanism for covering a lock in which the cover plate is held in its opened position during actuation of the lock and is only released to move back toward its closed position as the key is withdrawn from the lock key opening.